The proposed project extends an ongoing prospective longitudinal study of sick, pre-term infants, born to low-income parents, from the neonatal period through the first year of life, to include the next significant developmental stage, the period from age one to age three. It will test the durability and latent effects of a home-based intervention program which stops at age one and whose focus is on promoting pleasurable reciprocal interactions between infants at risk and their parents. In order to evaluate the effectiveness of our intervention program, there are 90 subjects divided into three study groups: an intervention group that received continuing parent/infant intervention services during the first year of life; a control group that did not receive intervention but did receive extensive longitudinal evaluation during that period equivalent to that administered to the experimental group, and an additional control group, a cross-sectional control group that is recruited at 13 months of age, does not receive the extensive longitudinal evaluations during the first year, but will participate in the assessment during age one to age three. The latter group is included to assess the effects of repeated early testing, as it is known that participation in a longitudinal research study in itself provides an intervention. In order to direct our intervention at a risk population, we have selected a group of infants who are at double jeopardy, both biologically and socially at risk. We do find that mothers' involvement and level of reciprocal interaction is increased in the intervention group in the first year of the infants' lives. Testing of the intervention program past the first year of life through age three is warranted to see whether there are latent effects of intervention, as new skills emerge for the infant, and as families adapt to life events, there will be assessments at 20, 30, and 42 months as to parental life situations, parental attitudes towards themselves and their infant, parent-child interaction and children's language, mastery motivation, positive sense of self and prosocial behavior.